The broad objective of this research proposal is to elucidate in a higher male primate, the rhesus monkey, the neuroendocrine mechanisms that govern the postnatal development of the control system regulating gonadotropin secretion, and thereby determine the onset of puberty. Specifically, we propose to determine if the hypothalamic control of LH and FSH secretion in the neonatal monkey is comparable to that which regulates gonadotropin secretion in the adult, and to determine the role of the pineal gland, the adrenal gland and extra hypothalamic limbic structures in the initiation of the suppression of gonadotropin secretion that is characteristic of the prepubertal state in higher primates. We also intend to provide a quantitative description of the time courses of the circulating gonadotropins, prolactin, and testosterone thhroughout development in intact and in agonadal animals.